Feed mechanism for machine tool

ABSTRACT

In the feed handle mechanism of a machine tool, a handle and a worm wheel are rotatably mounted on the handle shaft. A worm with an operating means at one end engages the worm wheel. The worm wheel is mutually rotatably fitted with a notched plate for transmitting the rotation. The space in the notch holds a rolling body which only transmits the rotation of the worm wheel to the rotation-transmitting plate. The notch also holds the transmitting member extending from the above mentioned handle and the transmitting member extending from the above mentioned handle shaft on both sides of the above mentioned rolling body.

Unite States Patent Kobayashl 1451 May 30,1972

[54] FEED MECHANISM FOR MACHINE 2,621,540 12/1952 Rath ..74/626 TOOL2,394,384 2/1946 Horstmann ..74/625 l, l [72] Inventor: AklyoshlKobayashi, Kariya, Japan 8 l 058 6/1931 Morgan 74/425 73 Assignee:Toyoda Koki Kabushiki Kaisha, Kariya, Primal? Examiner-William 1701393Japan Assistant ExaminerWesley S. Ratliff, Jr. [22] Filed: Jan. 1971Att0rneyC0nnolly & Hutz 1 App]. No.: 107,814 ABSTRACT In the feed handlemechanism of a machine tool, a handle and [30] Foreign A li ationPriorit D m a worm wheel are rotatably mounted on the handle shaft. Aworm with an operating means at one end engages the worm Jan. 22, Japane T e orm whe is ly rotatably fitted a 5 2 Us. CL H notched plate fortransmitting the rotation. The space in the i 5 l Int Cl I notch holds arolling body which only transmits the rotation of [58] Field of sea chthe worm wheel to the rotation-transmitting plate. The notch r 74/625425's also holds the transmitting member extending from the above [56] Rf mentioned handle and the transmitting member extending e erences cuedfrom the above mentioned handle shaft on both sides of the UNITED STATESPATENTS above mentioned rolling body.

465,892 12/1891 Smith ..74/625 4 Claims, 2 Drawing Figures Patented May30, 1972 3,665,786

2 Sheets-Sheet 1 FEED MECHANISM FOR MACHINE TOOL BACKGROUND OF THEINVENTION Most of the conventional feed handle mechanisms lack a finefeed device. Fine feed is usually executed on the hand feel" of a longexperience operator working the feed. it is therefore practicallyimpossible to make an extremely delicate infeed. Even with specialmechanisms equipped with fine feed devices work efficiency has not beensatisfactory because the handle shaft and the fine feed device must bedisconnected for the purpose of switching from coarse feed to fine feedor quickly reverting the handle.

SUMMARY OF THE INVENTION The general object of the present invention isto provide a highly improved feed handle mechanism which eliminates theneed for mechanical switching between coarse feed and fine feed.

Another object of the present invention is to provide simplifiedmechanical switching between fine and coarse feeds without disturbingthe manual feed device.

In accordance with the present invention a feed handle mechanism for amachine tool comprises a shaft with a handle rotatably mounted to theshaft. A rotation-transmitting plate is rotatably mounted about theshaft, and a hollow worm wheel rotates about the rotation-transmittingplate. A worm in engagement with the worm wheel is driven by a knobconnected thereto. The rotation-transmitting plate has at least onerecess on its periphery with a cam surface in the recess. A roller islocated between the inner wall of the hollow worm wheel and the camsurface of the recess, and the roller divides the recess into twochambers. A first member is drivingly connected to the handle andreceived in one of the two chambers, while a second member is drivinglyconnected to the handle shaft and received in the other of the chambers.A spring device disposed between the second member and the roller wedgesthe roller between the inner wall of the worm wheel and the cam surface.The first member is adapted to transmit rotation of the handle in onedirection to the handle shaft through the rotation-transmitting plateand the second member. The roller is adapted to transmit rotation of theworm wheel in the one direction through rotation of the worm to therotation-transmitting plate by wedged engagement thereof between theinner wall of the worm wheel and the cam surface of the recess. Also,the first member is adapted to transmit rotation of the handle in adirection opposite to the one direction to the handle shaft through theroller and the second member.

BRIEF DESCRIPTION OF THE DRAWING Novel features and advantages of thepresent invention in addition to those mentioned above will becomeapparent to those skilled in the art from a reading of the followingdetailed description in conjunction with the accompanying drawingwherein:

FIG. 1 is a longitudinal sectional view of a feed mechanism according tothe present invention; and

FIG. 2 is a cross sectional view taken along line 2-2 of FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION Referring in more particularity tothe drawing, FIG. 1 illustrates a bed 1 with a sliding table 2 freelyslidable on the bed adapted to support a workpiece (not shown). A manualfeed handle 3 is fitted on the front of the bed 1. A movable clutch 6arranged for manual-automatic switching is located on the in- Astationary clutch 23 opposite the movable clutch 6 is rotatably mountedto the shaft 5. The stationary clutch 23 and the movable clutch 6 arebrought into intimate engagement with one another when the movableclutch 6 is shifted to the right, as viewed in FIG 1, by manipulation ofthe switch knob 11. A pinion 32 is formed at the rear of the stationaryclutch 23. The pinion meshes with the rack piston 31 of an automaticfeed cylinder. Accordingly, when the automatic feed cylinder isoperated, the stationary clutch 23 is rotated by the rack piston 31 andits associated pinion 32. Such rotation is transmitted via the movableclutch 6 to the handle shaft 5, and further from a gear 19 fitted to theend of the shaft 5 to a gear 20 at the end of a second shaft 21. Thesecond shaft 21 is mounted parallel to the handle shaft Sand isconnected to a feed screw (not shown) which effects the infeed of agrinder table, as is well known in the art.

As shown best in FIG.. 2, a transmitting disc 24 is freely mounted onthe periphery of the stationary clutch 23. A rotatable cylinder 16integrated with a worm wheel 17 is fitted around the disc 24.symmetrically cut recesses 25, 25 having contact surfaces 27, 27 and 28,28 are located on part of the periphery of the disc 24. These recessesand the inside wall of the rotatable cylinder 16 enclose spaces 31, 31which house transmitting members 13, 13 that extend from the boss 4 ofthe handle 3. Moreover, the space 31, 31 house transmitting members 14,14 that extend from a rotation-transmitting cylinder 7 fitted to theoutside of the movable clutch 6 and in contact with the surfaces 28, 28of the recesses 25, 25. The gaps 31, 31 between the transmitting members13, 13 and 14, 14 are occupied by rollers 15, 15 held in wedgedengagement between the inside wall of the rotatable cylinder 16 and camsurfaces 25a, 25a of the recesses. Compression springs 26, 26 projectingfrom the sides of the transmitting members 14, 14 hold the rollers inwedged engagement. Accordingly, when the rotatable cylinder 16 is turnedclockwise, the rotation-transmitting disc 24 is also rotated clockwiseby the wedged engagement of the rollers 15,, 15. The rollers 15, 15 arein predetermined spaced relationship with the surfaces 13a, 13a of thetransmitting members 13, 13, and as explained more fully below, thisrelationship performs the fine feed of micron order when thetransmitting members 13, 13 are held in contact with the surfaces 27, 27of the recesses 25, 25. A contact plate 34 is fitted on thecircumferential surface of the rotationtransmitting cylinder 7 outsidethe movable clutch 6. One part of the contact plate 34 adjoins the sidesurface of the movable clutch 6. A switching device 9 parallel to thehandle shaft 5 is provided around the movable clutch 6, and theswitching device engages a pressing piece 10. Under the pressure of theswitching device 9 the pressing piece 10 presses the contact plate 34 onthe side of the rotation-transmitting cylinder 7 to thereby solidlyconnect the rotation-transmitting cylinder 7 to the movable clutch 6.Alternatively, the pressing piece may solidly connect the handle 3 tothe movable clutch 6 when the switching device 9 shifts the pressingpiece to the left, as viewed in FIG. 1.

A scale ring 8 is rotatably fitted on the outside of the boss 4 of thehandle 3. A knob 12 is provided for locking the scale ring 8 to thehandle. Additionally, the worm wheel 17 integrated with the rotationcylinder 16 meshes with a worm 29 rotatably mounted in a bearing 30. Afine feed dial 18 is fixed at one end of the worm 29, and the fine feeddevice comprises the worm 29 and the worm wheel 17.

The feed handle mechanism of the present invention functions in thefollowing manner. For the purpose of switching to manual operation, themovable clutch 6 is first disengaged from the stationary clutch 23through operation of the switching knob 11. In the drawing, the clutches6, 23 are in their automatic condition of being in contact with oneanother. The pressing piece 10 is moved against the contact plate 34 tolock the rotation-transmitting cylinder 7 to the movable clutch 6. Inthis condition, when the handle 3 is turned to the right, thetransmitting members 13, 13 that extend from theboss 4 of the handle 3bear against the contact surfaces 27, 27 of the rotation-transmittingdisc 24. The rotation-transmitting disc 24 being rotatingly supported bythe stationary clutch 23 is then turned clockwise, as viewed in FIG. 2.This rotation of the transmitting disc 24 causes the transmittingmembers 14, 14 bearing against the contact surfaces 28, 28 to rotate inthe same direction. Rotation of the transmitting members l4, 14 istransmitted from the rotation-transmitting cylinder 7 via the movableclutch 6, the handle shaft 5, and the gears 19, 20 to the second shaft21. Rotation of the second shaft 21 is transmitted to a feed screw (notshown) to thereby cause a coarse feed of the grinding table. As thegrinding table moves forward and the workpiece is finished close to thefinal dimensions, the handle 3 is no longer capable of making the finalmicron order fine feed.

For the purpose of accomplishing the fine feed, the fine feed dial 18 isturned so as to rotate the worm 29. The worm wheel 17 in meshingengagement with the worm 29 is then turned in a clockwise direction(FIG. 2) to thereby rotate the cylinder 16 fixed to the worm wheel.Clockwise rotation of the cylinder 16 is transmitted to the disc 24 bywedged engagement of the rollers l5, between the inside wall of therotatable cylinder 16 and the cam surfaces 25a, 25a of the recesses 25,25. Rotation of the disc 24 is transmitted to the members 14, 14 hearingagainst the contact surfaces 28, 28. Also, rotation of the members 14,14 is transmitted from the cylinder 7 via the movable clutch 6, thehandle shaft 5, and the gears 19, to the second shaft 21. The secondshaft drives the feed screw to thereby cause a fine feed of the grindertable.

For the purpose of quick reversion of the handle, the handle 3 isreversed to thereby turn the members 13, 13 in a counterclockwisedirection. The surfaces l3a, 13a press against the rollers 15, 15 andovercome the wedged engagement of the rollers 15, 15 and the force ofthe compression springs 26, 26 to push the rollers toward thetransmitting members 14, 14. Meanwhile, counterclockwise rotation of thetransmitting member 13 is transmitted via the rollers 15, 15 to themembers 14, 14. Thus, the rotation-transmitting disc 24 turns in thesame direction together with the transmitting members 14, 14. Rotationof the members 14 is transmitted from the rotation-transmitting cylinder7 via the movable clutch 6, the handle shaft 5, and the gears 19, 20 tothe second shaft 21. The second shaft operates the feed screw to therebyeffect quick reversion of the grinder table.

For the purpose of automatic operation, the pressing piece 10 and thecontact plate 34 are separated from one another through operation of theswitching device 9. The piece 10 is then pressed against the boss 4 ofthe handle 3, and the automatic-manual switch knob is operated to bringthe tapered surfaces of the clutches 6, 23 into engagement with oneanother. The automatic feed cylinder can then be operated to move therack piston 31 longitudinally to thereby produce an infeed of thegrinder table.

As described above, the present invention provides switching from manualcoarse feed to fine feed without disconnecting the handle shaft from thefine feed device. Also,

quick reversion of the handle is possible without such disconnection.

What is claimed is:

1. A feed mechanism for a machine tool comprising a shaft, a handlerotatably mounted about the shaft, a rotation-trans mitting platerotatably mounted about the shaft, a hollow worm wheel rotatably mountedon the rotation-transmitting plate, a worm in engagement with the wormwheel, a knob connected to drive the worm, the rotation-transmittingplate having on its peripheral surface at least one recess provided witha cam surface thereon, a roller located between the inner wall of thehollow worm wheel and the cam surface of the recess forming two chambersbetween the inner wall of the worm wheel and the recess of therotation-transmitting plate, a first member drivingly connected to thehandle and received in one of the two chambers, a second memberdrivingly connected to the handle shaft and received in the other of thechambers, and spring means dis d between the second member and theroller to wedge t e roller between the inner wall of the worm wheel andthe cam surface whereby the first member is adapted to transmit rotationof the handle in one direction to the handle shaft through therotation-transmitting plate and the second member, the roller is adaptedto transmit rotation of the worm wheel in the one direction by means ofrotation of the worm to the rotation-transmitting plate by wedgedengagement thereof between the inner wall of the worm wheel and the camsurface of the recess, and the first member is adapted to transmitrotation of the handle in a direction opposite to the one direction tothe handle shaft through the roller and the second member.

2. A feed mechanism as in claim 1 wherein the first member is inpredetermined spaced relationship with the roller when the first membertransmits the rotation of the handle in the one direction to the handleshaft.

3. A feed handle mechanism for a machine tool comprising a bed, a handleshaft rotatably mounted in the bed, a movable clutch slidably butnon-rotatably mounted on the handle shaft and having a tapered surfaceat one end thereof, a handle rotatably mounted on the movable clutch, astationary clutch rotatably mounted on the handle shaft and having atapered surface at one end thereof associated with the tapered surfaceof the movable clutch and a gear at the other end of the stationaryclutch, means for shifting the movable clutch axially relative to thehandle shaft for selective engagement between the tapered surfaces, ahydraulic cylinder including a piston rod with a rack in engagement withthe gear of the stationary clutch, a rotation-transmitting platerotatably mounted on the stationary clutch, a hollow worm wheelrotatably mounted on the rotation-transmitting plate, a worm inengagement with the worm wheel, a knob connected to drive the worm, therotation-transmitting plate having onits peripheral surface at least onerecess provided with a cam surface thereon, a roller located between theinner wall of the hollow worm wheel and the cam surface of the recessforming two chambers between the inner wall of the worm wheel and therecess of the rotation-transmitting plate, a first member drivinglyconnected to the handle and received in one of the two chambers, acylindrical member rotatably mounted on the movable clutch, a secondmember drivingly connected to the cylindrical member and received in theother of the chambers, means for selectively clamping the cylindricalmember to the movable clutch for rotation therewith, and spring meansdisposed between the second member and the roller to wedge the rollerbetween the inner wall of the worm wheel and the cam surface whereby thefirst member is adapted to transmit rotation of the handle in onedirection to the handle shaft through the rotation-transmitting plateand the second member, the roller is adapted to transmit rotation of theworm wheel in the one direction by means of rotation of the worm to therotationtransmitting plate by wedged engagement thereof between theinner wall of the worm wheel and the cam surface of the recess, and thefirst member is adapted to transmit rotation of the handle in adirection opposite to the one direction to the handle shaft through theroller and the second member.

4. A feed handle mechanism as in claim 3 wherein the first member is inpredetermined spaced relationship with the roller when the first membertransmits the rotation of the handle in the one direction to the handleshaft.

1. A feed mechanism for a machine tool comprising a shaft, a handlerotatably mounted about the shaft, a rotation-transmitting platerotatably mounted about the shaft, a hollow worm wheel rotatably mountedon the rotation-transmitting plate, a worm in engagement with the wormwheel, a knob connected to drive the worm, the rotation-transmittingplate having on its peripheral surface at least one recess provided witha cam surface thereon, a roller located between the inner wall of thehollow worm wheel and the cam surface of the recess forming two chambersbetween the inner wall of the worm wheel and the recess of therotationtransmitting plate, a first member drivingly connected to thehandle and received in one of the two chambers, a second memberdrivingly connected to the handle shaft and received in the other of thechambers, and spring means disposed between the second member and theroller to wedge the roller between the inner wall of the worm wheel andthe cam surface whereby the first member is adapted to transmit rotationof the handle in one direction to the handle shaft through therotation-transmitting plate and the second member, the roller is adaptedto transmit rotation of the worm wheel in the one direction by means ofrotation of the worm to the rotation-transmitting plate by wedgedengagement thereof between the inner wall of the worm wheel and the camsurface of the recess, and the first member is adapted to transmitrotation of the handle in a direction opposite to the one direction tothe handle shaft through the roller and the second member.
 2. A feedmechanism as in claim 1 wherein the first member is in predeterminedspaced relationship with the roller when the first member transmits therotation of the handle in the one direction to the handle shaft.
 3. Afeed handle mechanism for a machine tool comprising a bed, a handleshaft rotatably mounted in the bed, a movable clutch slidably butnon-rotatably mounted on the handle shaft and having a tapered surfaceat one end thereof, a handle rotatably mounted on the movable clutch, astationary clutch rotatably mounted on the handle shaft and having atapered surface at one end thereof associated with the tapered surfaceof the movable clutch and a gear at the other end of the stationaryclutch, means for shifting the movable clutch axially relative to thehandle shaft for selective engagement between the tapered surfaces, ahydraulic cylinder including a piston rod with a rack in engagement withthe gear of the stationary clutch, a rotation-transmitting platerotatably mounted on the stationary clutch, a hollow worm wheelrotatably mounted on the rotation-transmitting plate, a worm inengagement with the worm wheel, a knob connected to drive the worm, therotation-transmitting plate having on its peripheral surface at leastone recess provided with a cam surface thereon, a roller located betweenthe inner wall of the hollow worm wheel and the cam surface of therecess forming two chambers between the inner wall of the worm wheel andthe recess of the rotation-transmitting plate, a first member drivinglyconnected to the handle and received in one of the two chambers, acylindrical member rotatably mounted on the movable clutch, a secondmember drivingly connected to the cylindrical member and received in theother of the chambers, means for selectively clamping the cYlindricalmember to the movable clutch for rotation therewith, and spring meansdisposed between the second member and the roller to wedge the rollerbetween the inner wall of the worm wheel and the cam surface whereby thefirst member is adapted to transmit rotation of the handle in onedirection to the handle shaft through the rotation-transmitting plateand the second member, the roller is adapted to transmit rotation of theworm wheel in the one direction by means of rotation of the worm to therotation-transmitting plate by wedged engagement thereof between theinner wall of the worm wheel and the cam surface of the recess, and thefirst member is adapted to transmit rotation of the handle in adirection opposite to the one direction to the handle shaft through theroller and the second member.
 4. A feed handle mechanism as in claim 3wherein the first member is in predetermined spaced relationship withthe roller when the first member transmits the rotation of the handle inthe one direction to the handle shaft.